This invention relates to communications systems, and more particularly, to error detection and correction in communications systems.
Some known communications systems include such a large number of unique communications addresses that the addresses that are used have become lengthy, complex, incomprehensible, etc. For example, in the Internet, where an overwhelming number of addresses may exist, such difficulties with addressing may occur. Addressing techniques that are used for Internet systems may involve using a Uniform Resource Locator (“URL”) to specify a name uniquely identifying an address. Published rules and guidelines describe different URL schemes for the Internet and specify how URL's may be formed. The most common URL scheme is Hyper Text Transfer Protocol (“http”). Quite often a URL may include a lengthy combination of characters that may not be directly understandable by users. For example, a URL may include twenty or more alphanumeric characters and symbols for the address of a particular resource that may be available on the Internet. The following are URL's that are formed based on the http scheme with the related prefix punctuation mark “http://” omitted (which may typically be safely omitted in browser type applications):                www.symbol.com        www.symbol.com/products/        www.symbol.com/solutions/manufacturing/2d_label.html        www.google.com/search?q=symbol+technologiesThe first one of the above four addresses is typically referred to as a domain name. The second one of the four addresses is an address of a directory. For the first and second addresses, an Internet Web server may determine a filename for that address. For example, the filename may be determined to be one of the following: index.html (e.g., www.symbol.com/index.html), index.htm (e.g., www.symbol.com/products/index.htm), default.html (e.g., www.symbol.com/products/default.html), default.htm (e.g., www.symbol.com/default.htm), etc. The third address may be a complete URL with an exact filename and the fourth address may illustrate a query command in the http scheme.        
A URL may be provided to a user in printed form (e.g., on a business card, in a magazine advertisement, etc.). A URL that is provided in printed form may be entered by users by typing in or optically scanning in the URL. Typing or scanning may not provide sufficient accuracy in the entered URL.
A URL that is misspelled when entered may be too difficult to correct by visual inspection or otherwise. Visual inspection may be particularly tedious and inefficient when a lengthy URL that is entered based on a printed version of the URL is checked. When a URL is entered wrong, an incorrect Web page may be reached or an error message may be displayed. Such techniques may be deficient in informing users of a particular problem in a URL and may be deficient in establishing a desired communication without further user intervention.
Error detection and correction techniques have been developed and implemented in electronic systems. Some known detection and correction techniques have been used to check communications integrity and to provide redundancy when a communication is transmitted. Such known techniques have drawbacks, such as not providing correction and detection until a communication is received at a desired destination, not detecting an error when an inaccurate address has been entered wrong by a user, etc.